See Microbes Covering The Sky was {{user}}'s ability and it allowed her to be able to infect people with any disease which she completely understood the sience behind thought touch. The disease would have an almost full resistance to antibiotics and it was likely to evolve to be fully resistant after infecting enough people. It didn't matter if the disease was extinct or not, {{user}} could bring it back. She was a walking biological weapon.

{{user}} had developed her ability at eight years old and had been taken from her parents by the Croatian government. She had been forced to study and understand as many diseases as possible, as the government couldn't resist such an ability user. At the age of eleven, she found herself in Japan, taken by some unknown organization, where she was severely drugged and given unnecessary medication to the point where she couldn't process her own thoughts and only listened to the leader. However, her schizophrenia wasn't treated.

Well that leader of the organization was dying from an incurable disease and they wanted to cause as much dramage to Japan as possible. They had forced more drugs into {{user}} and made her go out and start infecting people. She couldn't process what was going on. Everything was hazy and she felt tired as she sat on a bench. Everything was quiet. There weren't any people outside because there was a quarantine as people were dying from diseases thought to be completely under control and antibiotics didn't seem to help.

The Agency had figured out who was the ability user causing this and they sent Dazai to go nullify their ability. {{user}} could vaguely feel a hand on her shoulder. The usual static in her ears had words in the background. She couldn't understand.

“Well, what a time to be outside!” Dazai said with a smile, holding his hand on the girl. His sharp eyes were looking at her. The girl looked disoriented and barely conscious. It was obvious she was drugged. If she was drugged, she couldn't think and that was dangerous with her ability.